Method of making combustible gas.



H. L. 'DOHERTY.

METHOD OF MAKING COMBUSTIBLE GAS.

APPLICATION FILED NOV. I5. 19!]. RENEWED APR.2B,1916.

1., 1 87.048 Patented June 13, 1916.

2 SHEETS-SHEET 1.

H. L. DOHERIY.

METHOD OF MAKING COMBUSTIBLE GAS.

APPLICATION FILED NOV. 15. I9I1. 1,187,048.

RENEWED APR. 28, I916.

Patented June 13, 1916.

2 SHEETSSHEET Z.

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W I D H X/QMAM mass withdrawn from HENRY I1. DOHEBTY,

OF NEW YORK, N. Y,

METHOD OF MAKING COMBUSTIBLE GAS.

Application flied November 15, 1911, Serial No. 660,449.

To all whom it may concern lie it known that I, HENRY L. Doilnn'rr, a citizen of the United States, and a resident of New York city, in the county of New York and State of New York, have invented certain new and useful Improvements in Methods of Making Combustible (has, of which the following is a specification.

This invention relates to methods of making combustible gas.

The objertspf my invention are to main tain the entire fuel bed of a producer, even when the producer is running on bituminous fuel, in an open condition comparatively free from ashes and therefore easily permeable by the blast, and to cool the fuel the producer by contacting with said mass a cooling fluid.

In my application Ser. No. (360.453, filed of even date herewith, I have described and 'laimcd the broad method of conducting combustion of which the herein claimed in vention is a specific modification adapted to the manufacture of combustible gas. The method of recuperating the heat of the material discharged'from the combustion region, herein disclosed, is a specific case un' der the broad method of recuperating the heat of hot solid material of which another specific application is disclosed in my application Ser. No. 535.841, filed Dec. 31st, 1909. In this latter modification of the method of heat recuperation adapted to be used with mat rial which will permit of contact with an oxidizing medium, I make use of air for transferring heat, In the modification of the method of returning .to the combustion region heat carried out of the sameby the material which has passed therethrough, which I use in the process herein claimed, the return of said heat is effected by the return to the combustion region of a portion of the gas therein generated.

In the accompanying drawings I have shown, in more or'less diagrammatic form, a battery of gas producers and appurtenances suitable for applying my invention.

Figure 1 is a vertical diametral section through one gas producer on the line A-B of Fig. 2 and line A'--B of Fig. 4 Fig. 2 is a diagrammatic plan of the apparatus showing 'the arrangement of the conduits, blowers, fuel elevators, etc. Fig. 3 is a partial front elevation of the apparatus. Fig yl is a front elevation'cf a single produeer on an enlarged scale showing the po- Specification of Letters Patent.

Patented June 13, 1916.

Renewed April 25. 1916. Serial No. 94,274.

sition of the gas iiues, etc. Fig. 5 is a vertical section through one of the recuperators of a producer on the line C-D of Fig. i showing the construction of the recuperators and heat interchangers.

Briefly stated, my invention comprises a method of operating a gas producer in which fuel from the mass in the producer is maintained in circulation (either intermittent or continuous) through the fuel chamber, the fuel being withdrawn at the bottom of the chamber, screened, and returned to the'producer at the top. The fuel, prior to being withdrawn at the bottom of the producer, is cooled advantageously by a current of gas from the carbon sing region which has been drawn up thrown the fresh fuel being supplied to the producer, the said fresh fuel being thus, at the same time, heated and the gas cooled.

My in'rention con'iprises also various other features which will be described below.

The amiiaraius shown comprises a battery of gas producers, numbered 1, 2. 3, 4, 5, 6, 7 and respectively.

.ieferring to the producer 4, which is shown in vertical cross-section in Fig. .1, 9

is the gasifying chamber, 10 the preheating chamber and 11 the cooling chamber. As

shown, the producer is constructed to operate with iateral draft, the inlet 12 for the primary current being located on one side of the producer in the gasifying chamber while the oili'ahe for the producer gas is l0- cated on the opposite. side of the gasifying chamber. thus giving the gas producing' current a flow across the producer. 14 is the ehargiu; opening at the top of the preheating chamber 10, closed by the come 15. '10 is the discharging door at the bottom of the cooling chamber. 17 is the main flue for carrying the primary draft current and which distributes the primary draft to the several producers in quantity controlled by the dampers 18. 19 is the principal producer gas flue into which all. the producers discharge. 20, 20, etc., are flues connecting 17 with source of combustion gases (the stack flues of steam boilers in the present case). 21 is a conveyor of any approved type which runs the length of the battery of producers and is so located that it will readily pick up the fuel mass discharged from the producers, transport it to the screening apparatus 22, and return the screened fuel, together with a portion of fresh fuel, to the charging hoppers of the producers. It is to be noted, however, that the particular fuel conveying means shown, though advantageous, is not essential to my invention, and many other types of conveyers may be substituted for the one shown. 23 is the chute for the screened material which discharges into the storage bin 21. 25 is the ash chute, which has branches 26 and 27, the former being the fine ash chute and the latter the coarse ash chute carrying of? the coarse particles which pass through the screen or grizzly 28. 29 is a pipe carrying air under a slight pressure and discharging it into the air box 30 beneath the screen or grizzly 28. This causes a strong current to discharge through the stream of coal passing over 28. The attrition between the particles and fragments of the mass tends to disintegrate the ash fragments into a more or less fine powder which is taken up by the air current and diverted into the chute 26. Ash particles too coarse to be taken up by the air, but small enough to pass through the interstices of 28, discharge through the chute 27. The ash may, of course, be directly discharged into cars and iinniediatel removed or carried away by some form 0 conveyer to the dump.

The coarser portion of the fuel discharges through the chute 23 into the bin 24. The re w coal is raised by the elevator 32 and discharged into the bin 33. By manipulating the gates 34 and 35 of 21 and 33 respectively, coked and raw fuel is discharged into the conveyer 21 which carries it along the tops of the producers and from which the fuel mixture is discharged into the preheating chambers of the producers as required. The

chute 23 is so arranged that the screened" fuel withdrawn from the producer may, when the bin 24 is full, be diverted through the chute 37 into the coke pockets 38. It is obvious that the producers may be operated to produce coke as well as gas when desired. This method of operation may be desirable when it is desired to produce a fairly rich comparatively high in illuminants. In this case, suiiicient bituminous coal is charged to give the desired volume of rich gas, the surplus coke produced being run to the pockets 38 or dumped on the ground to be removed as desired.

All or a portion of the relatively rich gas, consisting of a mixture of the producer gas drawn from the chamber 9 and the distillation gases of the bituminous coal resulting from the carbonization of the bituminous coal by the hot producer gas in the preheating chamber 10, which is taken off from 10 through the off-take 56, is drawn from 56 by the blower 65 through the connection 62 and forced through the pipe 59 into the inner flue 52 of the heat interchanger 51. Since the gas drawn oil through 56 is comparatively cool, it may be used instead of the flue gas from the recuperator stack 61, as explained below, to establish the necessary temperature differential between the two streams of gas in the heat interchanger, when the unaided action of the interchanger is insufficient to establish the desired differential. Valves G4 on 56 and 50 on 62 serve to regulate the portion of the comparatively rich gas which is drawn off of 10 which is sent to flue 52 of the heat interchanger and therefore mixed with the producer gas proper.

This manner of operating upon coal in an internally heated shaft or the like to manufacture coke and rich gas I do not claim specifically herein, it forming part of the matter of my co-pending application Ser. No- 660,451, filed Nov. 15th, 1911.

If the superficial area of the flue 52 should be insuflicient in any case to maintain a suflicient temperature difference between the ,gas in 52 and that flowing through 53, the

proper differential may be established by admitting to 52 through the pipe 59 either a portion of relatively cool flue gas from the stack 61 of the recuperator 58 or a portion of cold gas from the preheating chamber of the producer, as already explained. If flue gas is to be used to establish the necessary heat differential the valve 50 on the connection 62 is closed and valve 60 on the connection 31 is opened to the necessary extent. The gas will now be drawn by blower 65 through 31 from the pipe 66 which is connected with the stacks 61 of the recuperators, and forced through connection 59 to the flue 52 of the heat interchanger 51.

The admixture of the cold gas with the producer gas in 52 of course diminishes the temperature of the same to a degree corresponding to the proportion of cold gas introduced. When this mixture passes back through the flue 53 it still further reduces the temperature of the gas flowing to the fan owing to the fact that the mixture has a greater heat capacity (approximately pro portional to the quantity of cold gas intro ducediand for the same transference of heat from 52 to 53 does not change in temperature as much as the smaller volume of gas-passing through 52. To establish the desired ultimate temperature differential, therefore, it is not necessary for me to add the proportion of cold gas to the producer gas that would be required to establish such temperature by direct mixture, but a volume considerably less than this. It is obvious that I can not only use either the cool producer gas from 10 or the flue gas from 61 to establish a heat differential in the heat interchanger 51, when necessary, but a mixture of the two in any relative proportions.

T he method of handling hot gases by ordlnary far a described above I do not claim specifically herein, but will claim it in another a pplioation.

The method of operating my apparatus to carry out' my process as applied to producer 4 is as follows: A bed of ignited fuel is gradually built up in the producer in the well known manner. tions when starting up the producer an air connection, 79, is provided on the suction pipe 56 of blower 55, and valves and- 81 on 79 and 56, respectively. By means of these connections the blower 55 may be made to supply a draft current of air alone to the chamber 11 or a mixture of air and flue gas if desired. lVhen the ignited fuel has reached the top of the gasifying chamber the remainder of the fuel required to fill the )IO- ducer shaft may be rapidly charged. he

roducer is now in the proper condition for dpplying my process. Hot flue gas (from the boilers 39, 40, ll, 42, 4e, 44, 45 and 4c, in this case) flows into the main flue 17, and

thence passes through ,theconnections 12 to the gasifying region of the producers in connection with air. The air enters the recuperators through the air dampers (39,

thence passes through the air flues 7 O incontact with the walls of the flues 71 through which hot flue gas is passing, thence through the air oif-takes 72 to the cross-flue 73 and thence into the primary fine 12.

It is to be noted that offsets are made to the gasifying chamber 9 at the front and rear of the chamber, forming, respectively, a gas collecting chamber, 46', and a gas distributing chamber, 47, due to the fuel assuming its natural angle of repose. The primary draft current discharges from the fine 12 into the distributing space 47. Undcr the action of the fan 48 the primary current is drawn across the fuel column, set ting up a semi-combustion of the fuel. which forms producer gas as described in my Lettors Patent #829,105 and others. The oxygen of the air and the carbon dioxid of the flue gas react with part of the carbon of the fuel to form carbon monoxid. It is advantageous to use the greatest proportion of flue gas or steam. or a mixture of the two in the primary current that can'be used with outunduly reducing the temperature of the fuel bed in the producer. Owing to the fact, however. that the reaction of the carbon dioXid of the flue gas with the fuel in the producer absorbs a large quantity of heat it is necessary, with compamtival lo'u temperature flue gases, to add suificient air to the primary current to produce enough combustion of the fuel directly with oxygen-of the air to generate the" heat that is required to maintain. the temperature of the fuel bed. The relative proportions of flue gas and air in the primary draft are therefort so adjusted that the net heating effect of illfi draft current on the fuel bed will To facilitate operamaintain the latter at the temperature desired. In other Words, I burn the fuel in the producer by a draft current of balanced endothermic and'exothermic influence on the fuel, the balance of the two actions being so regulated that the temperature of the fuel bed may be maintained at the desired While I do not deem it so advantageous, I may substitute steam for flue gas as the endothermically reacting constituent of the primary draft current either wholly or partially. Or I may carry out the essential features of my process using a primary draft of air alone. When using steam instead of, or in admixture with flue gas as the endothermic constituent of the draft current, the damper 18 is closed and valve '77 on the steam connection75 opened to the desired degree. Steam now flows from the steam main 78 through the connection 75 and nozzle 76 into the primary flue of the producer inducing a flow of combustion gas through 12 in quantity regulated by damper 18. Air at the same time flows to the producer through the same fines as before. By [noperly regulating the valve 77 the composition of the primary draft current may be regulated to produce the desired effect upon the fuel bed. By entirely closing damper 18, the draft current will, of course, be composed of steam and air alone.

The nitrogen of the primary current and the products of the reactions with the carbon of the fuel form the producer gas. which 0 collects in the space 40' and is drawn through the fines l3 and 49 to the flue 52'of the heat interchanger 51. This heat interchanger 51 in the arrangement shown consists of an inner flue, 52, enveloped by an outer fine. 53. The blower-48 islocated opposite the front end of the flue 52 in the open space establishing communication between 52 and 53. 48 is driven by the motor 54.

lVhen starting normal operations, the setn ting being relatively cool, the gas drawn to the fan 48 (which gas generally leaves the producer at about 1200-1400 F.) is cooled down to a temperature which will not injure the fan. This gas passing backQirough theouter fine 53 serves to cool the portion of gas following it to the fan in its turn. In other words. there is effected an interchange of heat between the gas flowing to the fan and the gas discharging from the fan. By

this device I am able to use a fan of the ordinary type to establish the necessary draft through the fuel bed and flues without sacrificing any of the heat of the gas. The

reheated gas passes from 53 to the ,placeof 25 -use-1n this case, the combustion chamber of the boiler cooperating with the producer 4. g

In establishing the composition of the primary draft current I aim to use'the maxi- 4 mum quantity of flue gas or steam, or steam and flue gas, in the mixture that I can without unduly reducing the temperature of the fuel bed. If for any reason preferred, however, stea'm may be substituted for flue gas in the primary current to control the temperature of the fuel bed. The flue gas in this case being only at a temperature of about 700 F. initially, it is necessary to add air to the primary current unless the flue gas itself carries a sufiicient excess of air,

due to over-ventilation, to maintain the temperature of the fuel bed. The proportion of free oxygen that is required varies with the temperature, velocity of the draft current, character of the fuel, etc., and no fixed proportion of steam and CO to O can be prescribed. I mav state, however, in a general way, that with a temperature of 700 F. initially the proportion of (O to O should be approximately 1 to 1. In other Words,

the primary current should contain about 10% of each of the ingredients.

By means of the small positive pressure blower 55 a portion of the primary current in normal operation is diverted from the main stream and drawn up through the preheating chamber 10 in contact with the cold fuel filling the same. The gases of the so primary current which enter the producer 'carbonize the fresh char current being, in its *a'rn. ooled. Slnce th1s diverted stream passes through a considerable thickness of incandescent coke the reactive constituents of this subdivision of the draft current react to some extent with the carbon of the fuel so that the gas with drawn from the top of the preheater through the passage 56 is a poor producer 'gas carrying the uncondensable distillation gases from the raw coal. The gas thus withdrawn from the top of the'producer is forced by the blower 55 (which is preferably of the positive type) through the passage 57 into the lower part of the cooler 11 of the producer. It ascends through the fuel mass occupying 11 and cools it. The fuel discharges from the chamber 9 into 11 at a temperature around 1500 F. This is sufficient to cause the remaining CO, and moisture of the gas current ascending through 11 to react with a portion of the glowing coke to form GO, and H also whenwater vapor-ispresent, subjecting the mass of the coke andash to a cooling action which may extend down to 1300 F. or thereabout. The

cooling of-the fuel mass below this temperature is accomplished by the abstraction heat therefrom by the initially cold gas stream. In other Words, there is an inter change of heat between the fuel and the fuel being cooled down nearly t1 2 pheric temperature by the time it the lower part of the cooler while is heated nearly to the temperature fuel in the gasifying zone 9 by the 1 it reaches it. Passing through the g ing zone, the conversion of this s into the producer gas is comp volume of gas drawn off through troduced at the bottom of the coo e. be only that required to cool the fuel.

Under some circumstances it may be more convenient to substitute cold stack gas for the cool gas drawn off from the preh .ting chamber 10.v It is to be understood, however, such modification of my invention is intended to be covered by claims as well as the preferred form. \Vhen this modification of the method of operation is preferred, valve 64 is closed, and valve 67 on the connection 68 from the flue gas pipe 68 to the suction pipe 56 of blower is opened. Relatively cool flue gas will now be (n-a i down from the recuperator stacks and few through the pipe 57 into the lower pa cooler 11,quenching the unburned fis the material in 11, and cooling the Sal-.1 and the ash residue from the fuel burned in chamber 9 down to somewhere near the temperature at which the flue gas is introduced into 11.

When flue gas is used to cool the material in 11 as described above the circulation of gas through 10 to preheat the fuel is efiected by the blower The valve 64 being closed the cooled gas from 10 passes from 56 through the pipe 62 (valve 50 being opened) and is forced by the blower 65 either through the pipe 59 into the main current of producer gas flowing throu h the heat interchanger, or else (valve 4 being shut and valve 83 open) .through the branch 82 of 59 to a holder, orany place desired.

. During the carbonization of the raw fuel of the charge in the lower part of the pre heater l0 volatile matters of the same are given off and condense again in the portion of the fuel mass higher up. The condensed liquid is absorbed by the coke of the charge and carried down in the fragments of the coke into the hotter part of the producer where the heat is sufficient to crack tarry liquids carried down into'permanent gas and free carbon as the vaporized liquids are driven off from the coke. The permanent gases thus formed mingle With the gases assing through the preheater and are thereore drawn off through 56, while the liberated carbon is deposited in the pores of the coke, imparting to the same a greater hard ness and density than llf'WOuld otherwise have. In passing through the chamber 9 in contact with the hot coke, the hydrocarbon gases originally formed are still further cracked. forming ultimately chiefly methane and hydrogen. These constituents add considerably to the calorific value of the producer gas generated( It is obvious that all danger of a stoppage of the draft through 10 by the tar condensed therein may be avoided by simply insuring the presence of a sufficient proportion of coke in the charge. Since the coke is introduced into the producer cold and the weight of the coal charged is nearlonethird greater than that of the coke (erived from it, it is apparent thatit will always be easy to obtain sufficient cool gas to cool the discharging fuel mass. No matter what the speed at which the fuel is passed through the producer, therefore, the residual coke and ash-can always be withdrawn below the temperature of ignition of the former, and, in fact, comparatively cool. There is, there fore no appreciable loss in the thermal economy of the producer through the use of a comparatively large proportion of coke in the charge. On the other hand, there is of course a limit to the speed at which the fuel may be passed through the producer and this speed is that beyond which it is not possible' to carry out the thermal operations of the producer owing to an insufficiency of the time of contact between the fuel and gaseous streams.

The fremieucy with which the producer is drawn and charged will, of cmirse, rary with the conditions and the judgimrut of the operator. I consider that ho interval be tween tu zx-cix'e thaws sh uld be so fixed that not is. than 18 inches ol the charge column may be withdrawn at one operation, although the interval may he made less, if desired.

It is to he noted that tlwair for the primary current is preheated in the recuperator 55%, by that p rtion of the boiler line gas going to the stack, before being introduced into the primary draft ilues. The air used to support the combustion in the combustion chambers of the boilers may also be preheated in the recuperator It is to be noted that my invention entirely does away with the customayy asl. bed in the producer. At no time should the free ashes in the fuel mass in the cooler cX- ceed say 30% of thrwholr. With a proportion of f it? Ildl in (RT may cause more or obstruction to draft. I prefer to -o p which the fuel is rru mind that the proportion of free ashes uiil not be abov if}. The ash, therefor exercises practicaily no effect in interfering with the blast and, emcethe coke is present for the most part in ood sized lumps, the draft resistance of the charge in my producer with proper driving may be practically negligible.

I do not limit myself to the exact construction of the producer shown. For instance, the section of either or both the gasifying and preheating chamber might be made elliptical; or the preheating chamber might be made of circular section with an elliptical or rectangular discharge passage to the generating chamber. The essential requirement as to dimensions being simply that the fuel inlet assage to the gas-generating chamber shal have one cross-dimensibn longer than that of the generating chamber so that. the fuel in the latter chamber will form two 0 posed surfaces having the natural angle 0 repose of the fuel in the chamber.

Having described my invention, what I claim is:

1. In the manufacture of combustible gas the process which comprises, transmitting a body of fuel ast and in contact with an oxidizing dra tscurrent, said draft current being of such nature and in such volume as to form combustible gas with a portion of the fuel of said fuel body, said fuel being transmitted therepast'at a rate materially greater than the rate of combustion of said fuel by said draft current, collecting and removing a portion of the combustible gas formed and withdrawing in contact with the fuel in that portion of said fuel body which has not been subjected to combustion by said draft current another portion of the combustible gas formed to cool said portion of combustible gas, and passing cooled combustible gas in contact with that portion of said fuel body which has been subjected to partial combustion by said draft current, to cool said portion of said fuel body.

2. In the manufacture of combustible gas the process which comprises, transmitting a body of fuel tpast and in contact wit an oxidizing dra t current, said draft current being of Such nature and in such volume as to form combustible gas with a portion of the fuel of said fuel body, said fuel being transmitted there-past at a rate materially greater than the rate of combustibn of said fuel by said draft current, colldcting and removing a portion of the combustible gas formed and withdrawingdti contact with the fuel in that portion of said fuel body which has not been subjected to combustion by said draft current another portion of the combustible gas formed to cool said portion of combustible gas, and passing cooled combusti -ie gas in contact with that portion of said fuel body which has been subjected to paztial combustion by said draft current, to cool said portion of said fuel body, the volume of said portion of cooled combustible gas being regulated to that required to cool the said material down to the desired temperature.

3. In the manufacture of combustible gas the process which comprises, transmitting a bod of fuel past and in contact with an oxi izing draft current, said draft current being of such nature and ,in such volume as to form combustible gas with a portion of the fuel of said fuel body, said fuel being transmitted therepast at a rate materially greater than the rate of combustion of said fuel by said draft current, collecting and removin a portion of the combustible gas forme and withdrawing in contact with the fuel in thatportion of said fuel body which has not been subjected to combustion by said draft current another portion of the combustible as formed to cool said portion of combusti le gas, passing the so-cooled combustible gas in contact with that portion of said fuel body which has been subjected to partial combustion by said draft current, to

cool said portion of said fuel body and to re-heat the said portion of combustible gas, returning the re-heated combustible gas to the main current of combustible gas, and withdrawing the said main current from .contact with said fuel body.

4. In the manufacture of combustible gas the processwhich comprises, transmitting a body of fuel past and in contact with an oxidizing draft current, said draft current being of such nature and in such volume as to form combustible gas with a portion of the fuel of said fuel body, said fuel being transmitted therepast at a rate materially greater than the rate of combustion of said fuel by said draft current, collecting and removing, a portion of the combustible gas formed and withdrawing in contact with the fuel in that portion of said fuel body which has notbeen subjected to combustion by said draft current another portion of the combustible gas formed to cool said portion of combustible gas, passing cooled combustible gas in con tact with that portion of said fuel body which has been subjected to partial combus tion by said draft current, to cool said portion of said fuel body, withdrawing the said cooled portion of said fuel body, separating the comparatively coarse portion of said ma tcrial from the relatively fine portion of the same amlreturning the said coarse portion to said fuel body in admixture with a' regulated .proportion of fresh fuel.

5. In the manufacture of combustible gas the process which comprises, transmitting a body of fuel past and in contact with an oxidizing draft current, said draft current being of such nature and in such "olumc as to form combustible gas with a portion of said fuel body, said fuel being transmitted thcrepust at a rate such that unconsumed fuel shall constitute the major portion of the said uel body after the same has been trans mitted past said draft current, collecting and removing a portion of the combustible gas formed and withdrawing in contact with the fuel in that portion of said fuel body which has not been subjected to combustion by said draft current another portion of the combustible gas formed to cool said portion of combustible gas, and passing cooled combustible gas in contact with that portion of said fuel body which has been subjected to partial combustion by said draft current, to cool said portion of said fuel body.

6. In the manufacture of combustible gas the process which comprises, transmitting a body of fuel past and in contact with an oxidizing draft current, said draft current being of such nature and in such volume as to form combustible gas with a portion of said fuel body, said fuel being transmitted therepast-at a rate such that unconsumed fuel shall constitute the major portion of the said fuel body after the same has been transmitted past said draft current, collecting and removing a portion of th. combustible gas formed and withdrawing in contact with the fuel in that portion of said fuel body which has not been ,subjected to combustion by said draft current another portion of the combustible? gas formed to cool said portion of combustible gas, passing cooled combustible gas in contact with that portion of said fuel body which has been subjected to partial combustion by said draft current, to cool said portion of said fuel body, separating the unconsumed fuel in the said cooled portion of said fuelbody from the ash in the same and returning the said unburned portion to said fuel body in admixture with a regulated proportion of fresh fuel.

7. In the manufacture of combustible gas the process which comprises. transmitting a body of fuel past and in contact with an oxidizing draft. current, said current being of such nature and. in such volume as to form combustible gas with a portion of said fuel body said fuel being transniitted therepast at a rate such that unconsumed fuel shall constitute per cent. or more of said fuel body after the same has been transmitted past said draft current, collecting and removing a portion of the combustible gas formed and withdrawing in contact with the fuel in that portion of said fuel. body which has not been subjected e combustion by said draft current another poi tion of the combustible gas formed to cool said portion of combustible gas, and passing cooled combustible gas in contact with that portion of said fuel body which has been subjected to partial combustion by said draft current. to cool said portion of said fuel body.

8. In the manufacture of combustible gas the process which comprises, transmitting a fuel shall constitute 70 per cent. or more of that portion of said fuel body after the same has been transmitted past said draft current, collecting and removing a portion of the combustible gas. formed and withdrawing in contact with the fuel in that portion of said fuel body which has not been subjected to combustion by said draft current another portion of the combustible gas formed to. 0001 said portion of combustible gas, passing cooled combustible gas in contact with said fuel body whidi has been subjected to partial combustion by said draft current, to cool said portion of said fuel body, separating the unconsumed fuel in the said cooled portion of said fuel body from the ash in the same and returning the said unburned portion of said fuel body in admixture with a regulated proportion of fresh fuel.

9. In the manufacture of combustible gas the process which comprises, transmitting a body of fuel past and in contact with an oxidizing draft current, said draft current being of such nature and in such volume as to form: combustible gas with a portion of said fuel body, said fuel being transmitted thef'epast at a rate-such that unconsumed fuelshall constitute the major portion of the said fuel body after the same has been transmitted past said draft current, collecting and removing a portion of the combustible gas formed and withdrawing in contact with the fuel in that portion of said fuel body which has not been subjected to combustion by said draft current another portion of the combust ale ga's formed to cool said portion; of combustible gas, passing combustible gasin contact with that ortion of said fuel body which has beer?" jected to partial'combustion by said draft current. to cool said portion of said fuel body, separating the unconsumed fuel in the said cooled portion of said fuel body from the ash in the same and returning the said unburned portilm to said fuel body in adniixtilre with .a regulated proportion of fresh fuel, the proportion of the returned fuel in said mixture being that which will reduce the caking, of the fresh fuel to the desired degree.

10. In the manufacture of combustible gas the process which comprises, transmitting: a body comprising fresh and carbom l6 fuel in admixture past and in contact with an oxidizing draft current, said draft current being of such nature and. in such volume as to form combustible gas with a portion of said fuel body, said fuel being transmitted therepast at a rate such that unconsumed fuel shall constitute per cent. or more of said fuel body after the same has been transmitted past said draft current, collecting and removing a portion. of the (.Ullllllltilllllt) gas formed and with drawing in contact. with the fuel in that portion of said fuel body which has not been subjected to combustion by said draft rurrent another portion of the con'ihustible gas formed to co l said portion of combustibh gas, and passing cooled combustible gas in contact with that portion of said fuel body which has been subjected to partial combustion by said draft current. to cool said portion of said fuel bmly.

11. The process of making combustible gas which comprises, maintaining a body of fuel'in a relatively long body or mass, maintaining a scmicomlu1stion in an inter mediate combustion region of said fuel body or mass by passing through the fuel body in said region an oxidizing draft current, advancing the said fuel body through said ombustion region at a rate such that tln. portion of said body that has been ad- \anced beyond said combustion region shal consist in major part of unburned but car bonized fuel. miller-ting: and removing a portion of the combustible gas formed, withdrawing another portion of the gases of semiecombustion generated in the said corn" bustion region from the same, contacting the said portion of said gar-res with the portion of said fuel body advancing toward said combustion region, to cool said portion of gases and to preheat the said portion of said fuel body. contacting the said portion of cooled gases with the portion of the said fuel body that has advanced beyond said combustion region to quench and to cool the material of said portion of said fuel body, withdrawing the cooled material from said fuel body, separating the unburned fuel from the ash of said material. mixing the no said unburned fuel with a regulated 'portion of fresh fuel and adding the fuel mixture to that portion of said fuel body which is advancing toward said combustion region.

12. The process of making combustible gas which comprises, maintaining a body of fuel in a relatively long body or mass, maintaining a semi-combustion in an intermediate combusl ion region of said fuel-body or mass by passing through the fuel body 1:30 in said region an oxidizing draft current, advancing the said fuel body through said combustion region at a rate such that'the ggltion of said body that has been advanced 0nd said combustion region shall consist 1: i in major part of unburned but carbonized fuel, collecting and removing a portion of the combustible gas formed, withdrawing another portion of the gases of semi-combustion generated in the said combustion region from the same, contact/111g the said portion of said gases with theportion of said fuel body advancing toward said combustion region, to cool said portion of gases and to preheat the said portion of said fuel body, contacting the said portion of cooled gases with the portion of the said fuel body that has advanced beyond said combustion region to quench and to cool the material of said portion of said fuel body, the volume of the portion of'said gases of semicombustion withdrawn and cooled being that required to cool to the desired degree the said portion, of said fuel body, withdrawing the cooled material from said fuel body, separating the unburned fuel from the a sh of said material, mixing the said uninlrned fuel with a regulated portion of fresh fuel and adding the fuel mixture to n that portion of said fuel body which is'adrancing toward said combustion region.

13. The process of operating a gas-prodncer which comprises, passing the main draft current of the gas-producer across he 5 fuel bed of the same, collecting and rem ving a portion of the combustible gas formed, irhdrawing another portion of the gas. of the main draft current and passing said portion of gas in contact with a fresh por- {0 ti on of fuel intended to be consumed in said producer before the said portion of fuel has entered a gas-making region of said prmlucer, to cool. the said, portion of gas and to preheat the said portion of fuel. 5, withdrz'iwing unconsum ed but carbonized fuel and ash from the gas-making region of mid gasqnoducer, and passing the so-cooled portion of the gas in contact with the hot ll fuel and ash withdrawn from the ,uc-mahing region of said producer.

ll. The process of" operating a gas profi' which comprises, passing the main if; current of the gas-producer across the fuel bed of the same, collecting and removing a portion of the combustible gas formed, withdrawing another portion of the gas of the main. draft current and passing said p rtion of gas in contact with a fresh portion of fuel intended to be onsumed in w ll. producer before the said portion of fuel has entered the gas-making region of the said producer. to cool the said portion of gas and to preheat the said portion of furl, passing tlw fuel-mass through said producer at a rate n'mterially greater than that at which the reactive constituents of the said draft current react with said fuel, .\'l!ll=.l:;|\\'l!lg unconsumcd but carbonized for} and frrc ash from the gas-making rcnl said gusproducer, and passing the d ool l portion of gas in contact with mild uuconsumcd fuel and ash vitlr m from said gas-making region.

in, 'lln: n-ocees of operating a gas produce: uluch comprises, passing the main draft current of the gas-producer across the fuel bed of the same, collecting and removing a portion of the combustible as formed, withdrawing another portion 0 the main draft current and passing said portion of said draft current in contact with a portion of fuel intended to be. consumed in a gasproducer before the said portion has entered the gas-making region of the said producer, to preheat the said portion of fuel,

passing the fuel mass in said gas-producer through said main draft current at a rate greater than that at which the reactive constituents of. the said draft current react with said fuel, withdrawing the residual portion of said fuel mass from contact with said main draft current, passing cooled gaseous fluid in contact with the said residual portion of said fuel to cool the said residue and to heat the said portion of gaseous fluid, and passing the reheated gaseous fluid in contact with the fuel which is in contact with the said main draft current whereby the said gaseous fluid is added to thesaid draft current.

16. The process of operating a gas-producer which comprises, passing the main -draft current of the gas-producer across .the fuel bed of the same, collecting and removing a portion of the combustible gas formed, withdrawing another portion of the main draft current of the producer and passing said portion in contact with afresh portion of fuel intended to be consumed in said gas-producer before said portion of fuel has entered the gas-making region of the said gas-producer, to preheat the said portion of fuel and to cool said portion of said draft current, passing the fuel column of said gas-produce I- throughthe gas-producing region of tl'u same at a rate such that the mixture of'fuel and ash discharging from the said region will contain a major portion of unconsumed but carbonized fuel, withdrawing said mixture of carbonized fuel and ash, passing the said cooled portion of the said draft current in contact with the said mixture of fuel and ash, to quench the ignited fuel of said mixture, to cool the said mixture and to reheat the said portion of said draft current, and

passing the reheated portion of said draft current into the gas-making region of the said producer to rejoin the main draft current of the same.

17. The process of operating a gas-pro. duccr which comprises, passing the main draft current of the gas-producer across the fuel bed of said producer, collecting and removing a portion of the combustible gas formed. w thdraw l g another portion of the said main draft current of the producer and passing the said portion in contact with a portion of fuel intended to be consumed in said gas-producer before the said fuel has entered the gas-making region of the same, to cool the said portion of gas and to preheat the said portion of fuel, passing said preheated fuel through the gasanaking region of said producer at a rate such that the mixture of fuel and ash discharging from the said region will contain per cent. or more of unconsumed but carbonized fuel. withdrawing said mixture of carbonized fuel and ash from said gas-making region, passing the said cooled portion of said draft current in contact with the said mixture, to quench the ignited fuel of said mixture. to cool the said mixture and to reheat the said portion of said draft current, and passing the reheated draft current into the gasanaking region of the producer to rejoin the main draft current.

18. The method of manufacturing gas which comprises. maintaining a body of fuel in a relatively long body or mass. maintaining a Stlllifl)Illbllfitlull to produce combustible gas in a portion of the fuel in the said body in an intermediate region of said body located near the middle of said body or mass by passing laterally through the ignited fuel and across the. said body or mass an oxidizing draft current comprising balanced proportions of endothermically and exothermicall v' reacting constituents. withdrawing laterally combustible gas so formed, advancing the said body of fuel through said region of semicombiistion at a rate greater than the rate of combustion of said fuel therein. the rate of advance of said body relative to the rate of combustion being that which will maintain a major proportion of unconsumed but carbonized fuel and a minor proportion of ash in the residual material from said combustion. withdrawing said rcsidual material from the said region of semi-combustion. and contacting with the said residual mixture of fuel and ash a current of ga eous fluid. the volume of the said gaseou fluid relative to the quantity of said mixture of fuel and a h being that required to cool the said mixture to the desired dcgrce.

li The method of manufacturing gas which compri u iintaining a body initially compo ed of mixed carbonized and bituminous fuel in regulated proportions in a relatively long body or ma s. maintaining a semi-comlnlstion to produce combustible gas in an intermediate portion of the said fuel body located near the middle of the said body or lll2l by passing through said intermediate region '1 draft current com prising balanced proportions of endothermically and exothermically reacting constituents. withdrawing laterallycombustible gas so formed, advancing the aid fuel body through said region of semi-combustion at a rate greati-r than the rate of combustion therein. contacting with that portion of the said fuel body which has advanced beyond the said region of semi-combustion a relatively cool gaseous fluid to quench the car bonized fuel in said mixture and to cool the said fuel and ash, withdrawing the cooled mixture of carbonized fuel and ash from said body or mass, separating the ca bonized fuel from the ash of the said mixture and returning the said carbonized fu l in admixture with a regulated proportion of fresh fuel to the upper part of said fuel body.

20. The method of manufacturing combustible gas which comprises. maintaining a body of mixed carbonized and bituminous fuel in regulated proportions in a relatively long body or mass. maintaining a seno-combustion to produce combustible gas in an intermediate region of the said fuel body or mass by passing through the fuel body in said intermediate region an oxidizing draft current, said draft current compr sing flue gas and air in regulated proportions. the proportion of the v aid flue gas: to the air in said draft current being regulated with reference to their respective endothermic and exothermic action on the said fuel to maintain the said fuel at the temperature desired. withdrawing laterally combusti le gas so fornied. advancing the said body of fuel through the said region of semi-cranbustion at a rate greater than the rate of combustion of the said fuel therein. witlc drawing a major portion of the combu tildc as formed in said intermediate region from i the said body or mass. witlulrawiilg a llllll l' portion of the said combustible gas fiom said region, contacting the said minor pottion of the said combustibl gas with th portion of the said fuel body n the upper part of said body or mass film: the said region of semi-comlaistion. to arb-nn/e the bituminous, fuel in the said fuel body. t preheat the fuel body and to coo the aid minor portion of t'tllll ill lllil gir. \v'tl drawing the llll 'fllhlllilttl fuel and a h from the said region of scmiombust on. and cooling the said mixture of fuel and ash by contacting tht-iewith a iclatiwly cool gaseous fluid. 7

21. The method of manufacturing gas which comprises. maintaining a body of mixed carbonized and bituminous fuel in regulated proportions in a relatively long body or mass. maintaining. a SPIDl-(YUIIIlHh tion to produce combustible gas in a portion of the fuel in said body in an int imediate region of the said body or mass by I tlr-5llif through the said fuel in the said intermediate region an oxidizing draft current t )!llprising flue gas and air in regulated p oportions. withdrawing laterally combu t iblc gas so formed. advancing the said body of fuel through the said combustion region at a rate greater than the rate of comlaistiou of llO the said fuel therein, withdrawing the major portion of the combustible gas formed in the said intermediate region from the said body or mass, withdrawing the minor portion of the said combustible gas from the said region, contacting the said minor portion of the said combustible gas with that portion of said fuel body in the upper part thereof above tlm said region of semi-combustion, to carbonize the bituminous fuel in said portion of said fuel body, to preheat the said fuel body and to cool the said minor portion of combustible gas, conducting the socooled combustible gas to the lower portion of said. fuel body and contacting the said gas with the mixture of unburned fuel and ash withdrawn from the said intermediate regio .0 cool the said mixture and to reheat the 5,: id combustible gas, and mingling the so-heated combustible gas with the main body combustible gas.

The method of making gas which comprises, maintaining a body of fuel in a re itivelylong body or mass, said fuel compri ig mixed carbonized and bituminous fuei, maintaining a regulated combustion in an intermediate region of the said fuel body by passing through the fuel in said intermediate region a draft current c0mprising balanced proportions of exothermically and endothermically reacting constitucuts, the proportions of the said constituents of the said draft current being so regulated with respect to their exothermic and endothermic action on the fuel in the said intermediate region as to maintain the fuel body therein at the desired temperature, withdrawing laerally a major portion of the combustible gas formed, withdrawing another and minor portion of combustible gas produced in'said intermediate region, contacting the said minor portion of combustible with that portion of said fuel body which is advancing toward the said intermediate region, to carbonize the bituminous fuel in the said fuel body, to preheat the said body of fuel and to cool the said minor portion of combustible gas, contacting with the portion of the fuel body which has advanced beyond the said intermediate region the said cooled minor portion of combustible gas, to cool the said portion of the fuel body and to reheat the said minor portion of combustible gas, and returning the sorcheatcd minor portion of combustible gas to the said intermediate region of the said body or mass to join the main draft current passing theretbrougb.

1:3. The method of manufacturing gas which comprises, maintaining a body of mixed carbonized and bituminous fuel in regulated proportions in a relatively long bodv or mass, maintaining a semi-combustion in an intermediate region of the said fuel body by passing through the fuel in the said intermediate region an oxidizing draft current, withdrawing from such intermediate region a major portion of the combustible gas formed therein, advancing the said body of fuel through the said region of semi-combustion at a rate greater than the rate of combustion of the said fuel therein, the rate of advance of the said body relative to the rate of combustion in the said intermediate region being that which will maintain a major proportion of unconsumed but carbonized fuel and a minor proportion of ash in the material that has passed through the said intermediate region, withdrawing a minor portion of the combustible gas made in the said intermediate region, contacting the said minor portion of combustible gas with that portion of the said fuel body which is advancing toward the said region of semi-combustion, to Carbonize the bituminous fuel in the said portion of the said fuel body, to preheat the said portion of 7 said fuel body and to cool the said minor portion of combustible gas, cooling the mixture of carbonized fuel and ash which has advanced beyond the said region of semicombustion by contactin therewith the said cooled portion of com ustible gas, Withdrawing the cooled mixture of carbonized fuel and ash from the said body or mass, separating the carbonized fuel from the ash of said mixture and returning the said carbonized fuel in admixture with a regulated proportion of fresh bituminous fuel to the upper part of said fuel body.

24. The method of making combustible gas which comprises, maintaining a body of mixed carbonized and bituminous fuel in regulated proportions in a relatively long body or mass, maintaining a semi-combustion to produce combustible gas in a portion of the fuel in said body in an intermediate region of the said body or mass by passing through the said fuel body in said intermediate region an oxidizing draft current comprising balanced proportions of endothermically and exothermically reacting constituents, withdrawing from said intermediate region a major portion of the combustible gas formed therein, advancing the said body of fuel through the said intermediate rcgion at a rate greater than the rate of combustion in the said region, the rate of advance of the said body relative to the rate of combustion being that which will maintain a major hroportion of carbonized fuel and a minor proportion of ash in the residual material from the said combustion, witlr rawing the minor portion of the combustible gas formed in said intermediate region and passing the same in contact with that portion of the said fuel body which is advancing toward the said intermediate region, to carbonize the bituminous matter in said portion of said fuel body, to heat the said portion of the said fuel body and to cool the said minor portion of combustible gas, contacting with the mixture of carbonized fuel and ash which has advanced beyond the said intermediate region a current, of gaseous fluid. the volume of the said gaseous fluid relative, to the quantity of the said mixture of fuel and ash being that required to cool the said mixture to the desired degree.

25. The method of manufacturing combustible as which comprises, maintaining a body 0 mixed carbonized and bituminous fuel in regulated proportions in a relatively long body or mass, maintaining a semicombustion to produce comlmstible gas in an intermediate region of the said fuel body or mass by passing laterally through the fuel in the said intermediate region an oxidizing draft current, the said draft current comprising balanced proportions of endothermially and exothermically reacting constituents, withdrawing laterally a major portion of the combusti le gas formed in said intermediate region, advancing the said body of fuel through the said region of semi-combustion at a rate greater than the rate of combustion of the fuel therein, the rate of advance of said fuel relative to the rate of combustion being that which will maintain a major proportion ofunconsumed but carbonized fuel and a minor proportion of ash in the material advanced beyond the said region of scmi-coml ustion. withdraw: ing a minor portion of the combustible gas from the said region of semicombustion, contacting the said minor portion of combustible gas with that portion of said fuel body which is advancing toward the said region of semi-coinlais ion to carbonizc the bituminous matter in the said portion of said fuel body. to preheat the said portion of said fuel body and to cool the said minor portion of combir-tible gas, contacting the so-coolcd combustible gas with the mixture of fu l and ash advanced beyond the said region of semicon1bustion to cool said mixture and to reheat the said minor portion of combustible gas. and mingling the re heated minor portion of comlatstible gas with the main draft current passingthrough the said region of semi--comla|:-tion.

26. The method of mamil'acturing gas which comprises. maintaining a body of mixed carbonized and bituminou fuel in regulated proportions in a relatively long body or mass, maintaining a sclni-combnstion to rtduce combustible ga n a portion of the fuel .n the said body in an intermediatc region of the said fllc body or mass by passing laterally through thc ignited fuel in the said region an osidiziog draft current comprising balanced proportions of en dothermically and exothcrmically reacting constituents, the relative proportions of the said endothcrmically and exothermically reacting constituents being so regulated with respect to their reaction on the fuel in the said intermediate region as to maintain the fuel in the said region at the temperature desired. withdrawing laterally a major portion of the combustible gas formed in said intcrnualiate region. advancing the said body of fuel through the said region of semrcombastion at a rate greater than the rate of combustion of the said fuel in the said region. the rate of advance of said body relative to the rate of combustion in the said intcrnu-diate region being that which will maintain a major proportion ofunconsumed but carbonized fuel aml a minor proportion of ash in the material advanced beyond the said region of scmi-comliustion, withdrawing the major portion of the combustible gas formed from aid intermediate region. separately withdrawing the minor portion of the said combustible gas from said intermediate region aml contacting the said minor portion of the said combustible gas with that portion of the said fuel body which is advancing toward the said intermediate region. to carbonize the bituminous fuel in the said portion of the said fuel body. to preheat the said portion of the said fuel body and to cool the said minor portion of combustible gas. contacting with the mixture of carbonized fuel and ash which has advanced beyond the said intermediate rcgion a volume of relatively cool gaseous fluid to cool the said mixture of carbonized fuel and ash and to heat the said gaseous lluid. conducting the said gaseous fluid into said intermediate region and mingling the said tluid with the draft current passing through the said region. withdrawing the cooled mixture of carbonized fuel aml ash from the said body or mass. separating the carbonized fuel from the ash of the said mixture and returning the said carbonized fuel in admixture with a regulated proportion of fresh bituminous fuel to the part of the said fuel body which is advancing tw ward the said intermediate region.

LET. The method of manufacturing gas which comprises. maintaining a body of mixed carbonized and bituminous fuel in regulated proportions in a relatively long body or mass the proportion of said carbonized fucl relative to that of the bituminous fuel being that which will vaibstantially prevent the calting of the said bituminous furl. maintaining a Stlllld'flllll)llfiflflll to produce combustible gas in a portion of the fuel in said body which is in an intcrnu-diate 11-51301) f th s id body or mass bv passing laterally through the said portion of the said fuel body an oxidizing draft current comprising balanced proportions of endotlu-rmically and cxothermicall v reacting constituents, withdrawing laterally a major which will maintain a maior proportion of unconsumedbut carbonized fuel and a minor proportion of ash in the material advanced beyond the said region of semi-combustion, withdrawing the major portion of combustible gas from the said region of semi-combustion, separately withdrawing a minor portion of said combustible gas from the said region of semi-combustion, contacting the said minor portion of said combustible gas with that portion of the said fuel body which is advancing toward the said region of semi-combustion, to carbonize the bituminous matter in the said portion of said fuel body, to preheat the said portion of said fuel body and to cool the said minor portion of combustible gas, contacting with the mixture of carbonized fuel and ash which has been advanced beyond the said region of semi-combustion a regulated volume of a relatively cool gaseous fluid, said gaseous fluid comprising the said cooled minor portion of combustible gas the volume of the said gaseous fluid relative to the quantity of the said mixture of fuel and ash being that required to cool the said mixture to the desired degree, withdrawing the cooled mixture of carbonized fuel and ash from the vlower portion of the said fuel body or mass,

separating the carbonized fuel from the ash of the said mixture and returning the said carbonized fuel in admixture with a regulated proportion of fresh bituminous fuel to that part of the said fuel body which is advancing toward the said region of semi-combustion.

28. The method of manufacturing gas which comprises. maintaining a body of mixed carbonized and bituminous fuel in regulated proportions in a relatively long body or mass, the proportion of the carbonized fuel relative to that of the bituminous fuel in the said mixture being that which will substantially prevent the cuking of the said bituminous fuel, maintaining a semicombustion to produce combustible gas in a portion of the fuel in the said fuel body which is in an intermediate region of the said fuel body or mass by passing laterally through the ignited fuel and across the said body or mass in the said intermediate re gion an oxidizing draft current comprising balanced endothcrmically and exothermically reacting constituents. the proportion of the endothermically reacting constituent on the one hand and of the exothermidally reacting constituent on the other hand being so regulated with reference to thelr respective cooling and heating effects on the ig nited fuel in the said intermediate region that the temperature of the said fuel will be maintained at the point desired, withdrawing laterally a major portion of the combus tible gas formed in said intermediate region, advancing the said body of fllcl through the said region of semi-combustion at a rate greater than the rate of combos tion in the said region, withdrawing the minor portion of the combustible gas formed in the said intermediate region, contacting the said minor portion of the said combustible gas with that portion of the said fuel body in the upper part of the said fuel so body or mass which is advancing toward the said region of semi-combustion, to carbonize the bituminous matter in the said portion of the said fuel body, to preheat the said portion of the said fuel body and to cool the said minor portion of combustible gas tacting with that portion of the said fuel body which has advanced beyond the said re gion of semi-combustion a regulated volume of a gaseous fluid, the said fluid comprising a cooled minor portion of combustible gas, the volume of the said gaseous fluid relative to the quantity of the material in the said portion of the said fuel body being that required to cool the said material to the desired degree.

29. T he method of making combustible gas which comprises. maintaining a body of fuel in a relatively long body or mass, maintaining a semiwombustion to produce combustible gas in a portion of the fuel of the said body in an intermediate region of the said fuel body or mass by passing laterally through the ignited fuel and across the said body or mass in the said intermediate region an oxidizing draft current comprising baianced proportions of cndothermically and cxothermically reacting constituents, withdrawing laterally a major portion of the combustible gas formed in said intermediate region. advancing the said body of fuel through the said region of semi-comhustion at a rate greater than the rate of combust of the fuel in said region. the rate of vance of said body relative to the rats combustion being that which will mail, a major proportion of unconsumed but a bonized fuel and a minor proportion of in the material advanced beyond the s region of semirombustion. the said f i body being advanced by withdrawing rcgr lated portions of the same from the lower part of the said body or mass. withdrawing a minor portion of the combustible from the said intermediate region, contacting the said minor portion of combustible gas with that portion of the said fuel bodywhich is advancing toward the said region of semi-combustion, to carbonize the bitumi nous fuel in the said portion ofsaid fuel body: to preheat the said portion of said fuel body and to cool the saidmi-nor portion of combustible gas, contacting with the said mixture of carbonized fuel and ash which has advanced beyond the said region of seniiwombustion a relatively cool gaseous fluid. to quench the carbonized fuel in the said mixture. to cool the said fuel and ash and to heat the said gaseous fluid, conducting the SOlPZlttll gaseous fluid into the said region of semi-comlaistion and mingling the said fluid with the draft current passing through the said region. withdrawing the cooled mixture of carbonized fuel and ash from the said body or mass. separating the carbonized fuel from the ash of the said mixture and returning the said carbonized fuel in admixture with a regulated proportion of fresh bituminous fuel to that part of the said fuel body which is advancing toward the said region of semi-combustion.

30. The method of making combustible gas which comprises, maintaining a body of mixed carbonized and bituminous fuel in regulated proportions in a relatively long body or mass, the proportion of the said carbonized fuel. relative to that of the bituminous fuel being that which will substantially prevent the caking of the said bituminous fuel, maintaining a semi-combustion to produce combustible gas of a portion of the fuel in said body in an intermediate region of the said fuel body or mass by passing through the portion of the fuel in the said intermediate region an oxidizing draft current comprising regulated proportions of flue gas and air, withdraw in from said intermediate region a major poi tion of the combustible gas formed therein, adi ancing the said body of fuel through the aid iegion of semi-combustion at a rate greater than the rate of combustion in said ri CNN, the rate of advance of the said body .eiat vu t1 the rate of combustion being that h -h u ill maintain a major proportion of unconsiuned but carbonized fuel and a minor proportion of ash in the material admnced be'a'ond the said region of semicombimtion, contacting with tie said fuel and ash mixture a relatively cool gaseous fluid. to quench the caibcnized fuel in the said mixture, to cool the said fuel and ash and o heat the said gaseous fluid, passing the so-heated gaseous fluid into the said intermediate region of the said fuel body or mass to mingle with the draft current passing through the said region, separating the carlmnized fuel from the ash of the said ooled mixture of fuel and ash and return ing the separated carbonized fuel in 2Itli|ii(- ture with a regulated proportion of frc bit'zr uoi-s fuel to the part of the said fu l h ulran ing' toward the said a 1 f mill'il 'i)lllljllfwii n il. ine method of naauutacturing gas which comprises, maintaining a body of mixed carbonized and bituminous fuel in regulated proportion in a relatively long body or mass, the proportion of the said carbonized fuel relativ to the bituminous fuel being that which will substantially prevent the caking of the said bituminous fuel, maintaining a semi-combustion to produce combustible gas in a portion of the fuel of said body in an intermediate region of the said fuel body or mass by passing through the said portion of fuel an oxidizing draft current comprising balanced proportions of endothermically and exothermically reacting constituents, said draft current comprising fiue gas and air in regulated proportions. the proportion of flue gas on the one hand and the air on the other hand being so regulated with reference to the cooling effect on the said ignited fuel of the flue gas and the heating effect of the air that the temperature of the said fuel in the said intermediate region will be maintained at the point desired, withdrawing from said intermediate region a major portion of the combustible formed therein, advancing the said body of fuel through the said interme diate region at a rate such that the portion of the said fuel body which has advanced beyond the said region of semi-combustion shall consist in major part of carbonized fuel and in minor part of ash, contacting with the said fuel and ash mixture a relatively cool gaseous fluid, to quench the carbonized fuel in said mixture, to cool the said fuel and ash and to heat the said gaseous fluid, conducting the so-heated gaseous fluid intothe said intermediate region and mingiing the said fluid with the draft current passing through the said region, separating the carbonized fuel from the ash of the said mixture and returning the said carbonized fuel in admixture with a regulated proportion of fresh bituminous fuel to that part of the said fuel body which is advancing toward the said intermediate region.

The method of manufacturing combustible gas which comprises, maintaining a body of fuel in a relatively long body or mass, maintaining a semi-combustion to produce combustible gas of a portion of the fuel in said body in an intermediate region of the said fuel body or mass by passing therethrough an oxidizing draft current comprising balanced proportions of endothermically and exothermically reacting constituents. said draft current comprising flue gas and air in regulated proportions, the proportion of flue gas on the one hand and air on the other hand being so regulated with reference to the cooling ctfect on the ignited fuel in th said intermediate region of the line ga and the heating effect of the air that the tt'tlll'ililtlll'e of the fuel in the said internu'diale region will be maintained at the point desired, withdrawing from said intermediate region a major portion of the combustible gas formed therein, advancing the said body of fuel through the said region of semi-combustion by withdrawing regulated portions of the material advanced beyond the said region of semi-combustion from the lower part of the said fuel body or mass, withdrawing a minor portion of the combustible gas formed in the said region of semicombustion, contacting the said minor portion of combustible gas with that portion of the said fuel body which is advancing toward the said region of semicombustion, Contacting with that portion of the said fuel body which has advanced beyond the said region of semi-combustion a relatively cool gaseous fluid, to quench the carlmnized fuel in the said portion of said fuel body, 'to cool the said portion of said .to the said portion of the said fuel body being that required to cool the material of the said portion of the said fuel body to the desired degree, and conducting the so-heated gaseous fluid into the said region of semicombustion and mingling the said fluid with the draft current passing through the said region.

Signed at New York city in the county of New York and State of New York, this 14th day of Nov., A. D. 1911.

HENRY L. DoHERTYQ 'VVitnesses:

FRANK L. BLACKBURN, H. A. MACKENZIE. 

